cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 13 results. Next

A215732 a(n) is the first digit to appear n times in succession in a power of 2.

Original entry on oeis.org

1, 5, 7, 5, 6, 8, 7, 1, 9, 9, 6, 3, 2, 9, 1, 4, 1
Offset: 1

Views

Author

V. Raman, Aug 22 2012

Keywords

Comments

Assumes that there are no 2 digits that appear n times in succession for the first time in the same power of 2. - Chai Wah Wu, Apr 26 2019

Examples

			2^16 = 65536 is the first power of 2 with a repeated digit (cf. A045875), with 5 repeated, so a(2) = 5. - _N. J. A. Sloane_, Aug 23 2012
		

Crossrefs

Programs

  • Mathematica
    n = 1; x = 1; lst = {};
    For[i = 1, i <= 10000, i++,
    z = Split[IntegerDigits[x]]; a = Length /@ z; b = Max[a];
    For[j = n, j <= b, j++,
      AppendTo[lst, First[First[Part[z, First[Position[a, b]]]]]]; n++
    ]; x = 2 x ]; lst (* Robert Price, Mar 16 2019 *)
  • Python
    def A215732(n):
        l, x = [str(d)*n for d in range(10)], 1
        for m in range(10**9):
            s = str(x)
            for k in range(10):
                if l[k] in s:
                    return k
            x *= 2
        return 'search limit reached'
    # Chai Wah Wu, Dec 17 2014

Extensions

a(11)-a(13) added by T. D. Noe, Sep 04 2012
a(14) added by T. D. Noe, Sep 06 2012
a(15) from Bert Dobbelaere, Feb 25 2019
a(16) from Paul Geneau de Lamarlière, Jun 26 2024
a(17) from Paul Geneau de Lamarlière, Sep 24 2024

A215727 a(n) is the smallest m for which 3^m contains n consecutive identical digits.

Original entry on oeis.org

0, 11, 32, 33, 274, 538, 2124, 7720, 22791, 107187, 107187, 639226, 5756979, 8885853, 68353787, 78927180, 78927180
Offset: 1

Views

Author

V. Raman, Aug 22 2012

Keywords

Comments

3^(a(16)+1) contains exactly 16 consecutive 3's. - Bert Dobbelaere, Mar 20 2019

Examples

			3^11 = 177147, which has two digits in a row.
		

Crossrefs

Programs

  • Mathematica
    A215727[n_] := Module[{m = 0 , t}, t = Table[i, {i, 0, 9}, {n}];
    While[True, If[ContainsAny[Subsequences[IntegerDigits[3^m], {n}], t], Return[m], m++]]; m]; Table[A215727[n], {n, 1, 14}] (* Robert Price, Oct 16 2018 *)
  • Python
    def A215727(n):
        l, x = [str(d)*n for d in range(10)], 1
        for m in range(10**9):
            s = str(x)
            for k in l:
                if k in s:
                    return m
            x *= 3
        return 'search limit reached'
    # Chai Wah Wu, Dec 17 2014

Extensions

a(12) from Chai Wah Wu, Dec 17 2014
a(13)-a(14) from Giovanni Resta, Apr 20 2016
a(15) from Bert Dobbelaere, Mar 04 2019
a(16)-a(17) from Bert Dobbelaere, Mar 20 2019

A217171 a(n) is the first digit (from the left) to appear six times in succession in the decimal representation n^A217161(n).

Original entry on oeis.org

8, 8, 7, 2, 1, 7, 7, 8, 0, 0, 0, 2, 4, 4, 7, 4, 6, 1, 0, 2, 9, 4, 4, 5, 9, 0, 7, 4, 0, 2, 3, 9, 4, 6, 8, 0, 3, 0, 0, 0, 6, 1, 1, 5, 3, 1, 6, 0, 0, 9, 0, 2, 7, 8, 4, 7, 6, 9, 0, 2, 5, 7, 7, 5, 9, 6, 4, 7, 0, 3, 4, 0, 4, 7, 3, 1, 2, 3, 0, 0, 0, 5, 1, 2, 3, 2, 1
Offset: 2

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Table[k = 1; While[d = IntegerDigits[n^k]; df = Partition[Differences[d], 5, 1]; ! MemberQ[df, {0, 0, 0, 0, 0}], k++]; d[[Position[df, {0, 0, 0, 0, 0}][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

A217167 a(n) is the first digit (from the left) to appear two times in succession in the decimal representation of n^A217157(n).

Original entry on oeis.org

5, 7, 5, 8, 7, 1, 4, 4, 0, 1, 4, 4, 4, 2, 5, 3, 8, 9, 0, 4, 2, 8, 3, 4, 1, 4, 7, 1, 0, 8, 3, 3, 1, 2, 6, 7, 4, 4, 0, 1, 8, 8, 4, 1, 1, 2, 1, 1, 0, 7, 1, 8, 1, 5, 4, 5, 3, 1, 0, 2, 4, 0, 4, 2, 6, 4, 4, 2, 0, 1, 0, 3, 2, 7, 7, 7, 5, 0, 0, 4, 5, 8, 1, 2, 0, 3, 8
Offset: 2

Views

Author

V. Raman, Sep 27 2012

Keywords

Comments

Note that 109^2 = 11881. So by looking at the digits from the left, we have a(109) = 1.

Crossrefs

Programs

  • Mathematica
    Table[k = 1; While[d = IntegerDigits[n^k]; ! MemberQ[df = Differences[d], 0], k++]; d[[Position[df, 0][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

A217168 a(n) is the first digit (from the left) to appear three times in succession in the decimal representation of n^A217158(n).

Original entry on oeis.org

7, 8, 7, 8, 7, 7, 7, 8, 0, 8, 1, 6, 1, 2, 7, 2, 2, 7, 0, 2, 8, 6, 7, 8, 4, 5, 6, 1, 0, 1, 7, 4, 7, 5, 6, 3, 4, 5, 0, 5, 1, 1, 7, 4, 5, 6, 5, 1, 0, 8, 5, 1, 1, 3, 0, 1, 0, 1, 0, 3, 8, 4, 7, 2, 9, 6, 8, 7, 0, 2, 2, 8, 2, 7, 3, 4, 5, 5, 0, 8, 7, 0, 7, 5, 2, 7, 2
Offset: 2

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Table[k = 1; While[d = IntegerDigits[n^k]; ! MemberQ[df = Partition[Differences[d], 2, 1], {0, 0}], k++]; d[[Position[df, {0, 0}][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

A217169 a(n) is the first digit (from the left) to appear four times in succession in the decimal representation of n^A217159(n).

Original entry on oeis.org

5, 5, 8, 7, 0, 9, 8, 5, 0, 7, 3, 6, 1, 2, 8, 9, 5, 1, 0, 4, 4, 7, 7, 8, 2, 5, 1, 0, 0, 9, 8, 6, 5, 5, 2, 6, 5, 6, 0, 9, 6, 7, 6, 5, 1, 6, 2, 2, 0, 6, 6, 3, 3, 1, 0, 3, 1, 1, 0, 7, 6, 2, 8, 3, 5, 9, 6, 8, 0, 1, 4, 8, 6, 3, 8, 1, 7, 9, 0, 5, 6, 9, 1, 2, 8, 1, 8
Offset: 2

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Table[k = 1; While[d = IntegerDigits[n^k]; df = Partition[Differences[d], 3, 1]; ! MemberQ[df, {0, 0, 0}], k++]; d[[Position[df, {0, 0, 0}][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

A217170 a(n) is the first digit (from the left) to appear five times in succession in the decimal representation of n^A217160(n).

Original entry on oeis.org

6, 5, 6, 4, 2, 5, 4, 5, 0, 6, 5, 4, 4, 1, 6, 5, 5, 9, 0, 2, 8, 6, 2, 5, 9, 2, 1, 8, 0, 2, 6, 8, 2, 6, 2, 6, 3, 8, 0, 8, 7, 0, 1, 7, 6, 3, 6, 5, 0, 6, 9, 6, 6, 9, 2, 2, 4, 4, 0, 4, 9, 4, 2, 3, 4, 4, 8, 5, 0, 2, 9, 9, 0, 9, 9, 0, 9, 6, 0, 0, 4, 9, 1, 0, 6, 1, 2
Offset: 2

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Table[k = 1; While[d = IntegerDigits[n^k]; df = Partition[Differences[d], 4, 1]; ! MemberQ[df, {0, 0, 0, 0}], k++]; d[[Position[df, {0, 0, 0, 0}][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

A217172 a(n) is the first digit (from the left) to appear seven times in succession in the decimal representation of n^A217162(n).

Original entry on oeis.org

7, 2, 7, 8, 2, 3, 7, 2, 0, 6, 4, 6, 3, 2, 7, 9, 4, 9, 0, 4, 2, 4, 5, 8, 4, 2, 5, 6, 0, 2, 2, 3, 8, 7, 2, 5, 3, 0, 0, 4, 1, 9, 2, 7, 0, 8, 1, 6, 0, 4, 4, 2, 1, 2, 3, 1, 3, 4, 0, 2, 8, 8, 7, 5, 1, 7, 6, 9, 0, 4, 8, 1, 7, 5, 9, 6, 4, 3, 0, 2, 1, 1, 7, 8, 7, 8, 8
Offset: 2

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Table[k = 1; While[d = IntegerDigits[n^k]; df = Partition[Differences[d], 6, 1]; ! MemberQ[df, {0, 0, 0, 0, 0, 0}],  k++]; d[[Position[df, {0, 0, 0, 0, 0, 0}][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

A217175 a(n) is the first digit (from the left) to appear n times in succession in the decimal representation of the Fibonacci(A217165(n)).

Original entry on oeis.org

0, 5, 7, 7, 1, 5, 7, 7, 3, 2, 4, 3, 4, 2, 4
Offset: 1

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    k = 0; Join[{0}, Table[While[d = IntegerDigits[Fibonacci[k]]; prt = Partition[Differences[d], n - 1, 1]; ! MemberQ[prt, Table[0, {n - 1}]], k++]; d[[Position[prt, Table[0, {n - 1}]][[1, 1]]]], {n, 2, 8}]] (* T. D. Noe, Oct 03 2012 *)
  • Python
    def A217175(n):
        if n == 1:
            return 0
        else:
            l, y, x = [str(d)*n for d in range(10)], 0, 1
            for m in range(1, 10**9):
                s = str(x)
                for k in range(10):
                    if l[k] in s:
                        return k
                y, x = x, y+x
            return 'search limit reached'
    # Chai Wah Wu, Dec 17 2014

Extensions

a(10)-a(11) from Chai Wah Wu, Dec 17 2014
a(12)-a(15) from Nick Hobson, Feb 14 2024

A217176 a(n) is the first digit (from the left) to appear n times in succession in the decimal representation of the Lucas(A217166(n)).

Original entry on oeis.org

2, 1, 3, 0, 2, 2, 9, 7, 2, 1, 1, 5, 5, 7, 7, 9
Offset: 1

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    k = 0; Join[{2}, Table[While[d = IntegerDigits[LucasL[k]]; prt = Partition[Differences[d], n - 1, 1]; ! MemberQ[prt, Table[0, {n - 1}]], k++]; d[[Position[prt, Table[0, {n - 1}]][[1, 1]]]], {n, 2, 8}]] (* T. D. Noe, Oct 03 2012 *)
  • Python
    def A217176(n):
        if n == 1:
            return 2
        else:
            l, y, x = [str(d)*n for d in range(10)], 2, 1
            for m in range(1, 10**9):
                s = str(x)
                for k in range(10):
                    if l[k] in s:
                        return k
                y, x = x, y+x
            return 'search limit reached'
    # Chai Wah Wu, Dec 17 2014

Extensions

a(11) from Chai Wah Wu, Dec 17 2014
a(12)-a(16) from Nick Hobson, Feb 03 2024
Showing 1-10 of 13 results. Next